Synthetic grass turf has long been used, in particular for urban furnishing, as paving for the surrounds of swimming pools and, in general, to replace natural grass in all those conditions in which the laying and maintenance of natural turf may be critical
The use of such synthetic grass has recently received new impetus in function of its use as turf for sports applications, for example for football fields. The literature in this connection is very extensive, as may be seen, in regard to patents, from the following documents: U.S. Pat. No. 3,731,923, U.S. Pat. No. 4,337,283, U.S. Pat. No. 5,958,527, U.S. Pat. No. 5,961,389, U.S. Pat. No. 5,976,645, JP-B-32 53 204, JP-A-10037122, DE-A-44 44 030, EP-A-0 377 925 and EP-A-1 158 099.
In particular, from the latter document, which is owned by the present applicant, a synthetic grass structure is known that comprises a substratum in sheet form with a plurality of filiform formations extending from the substratum to simulate grass and a particle-based filling material dispersed among the filiform formations so as to maintain said filiform formations in a substantially erect condition. Specifically, this structure of synthetic grass is characterised in that the particle-based filler material comprises a substantially uniform mass of granular material selected from the group comprising materials based on polyolefines and materials based on vinylic polymers.
Further advantageous developments of this solution have been described in documents EP-A-1 319 753, EP-A-1 375 750, EP-A-1 371 779 and EP-A-1 486 613, all of which are held by the present applicant.